The invention relates generally to sleds, and in particular, to the attachment of straps to a sled.
When riding a sled down a hill, a rider is often required to make rapid turns. These rapid turns result in g-forces that tend to throw the rider off the sled.
To avoid separating the sled from its rider, it is useful to provide a strap to secure the rider to the sled. Such a strap is typically anchored to the body of the sled by strap anchors. When in use, the strap absorbs the g-forces that would otherwise throw the rider off the sled, and transmits those forces to the body of the sled at the strap anchors.
In a known strap anchor, a bolt passes through a grommet at the end of the strap. The bolt then passes through a hole in the body of the sled. A nut then engages the bolt so that the body of the sled is held between the nut and the strap.
In use, the strap tends to rotate about the axis defined by the bolt. This rotation causes small amounts of torque to be transmitted to the bold. In many cases, the cumulative effect of these incremental torques is to work the nut loose. Unless it is periodically tightened, the nut can fall off the bolt and into the snow.
Among the forces transmitted by the strap to the anchor are those that act in a direction orthogonal to the bolt. These forces, referred to herein as xe2x80x9cshear forces,xe2x80x9d cause the bolt to pivot about a fulcrum defined by the contact area between the bolt and the sled body. The cumulative effect of such pivoting can likewise result in failure of the strap anchor.
A sled incorporating the invention eliminates the fulcrum about which the bolt can pivot and thereby provides a more secure way to attach a strap to a hull of the sled. Such a sled includes a hull having an inboard hole and a lip that extends outwardly from the hull. The lip has an outboard hole opposed to the inboard hole. A support member extends through a strap hole in a strap, through the inboard hole, and through the outboard hole.
In one embodiment, two fins extend outward from the hull. These fins are disposed on either side of the inboard hole.
In another aspect, the sled includes a hull having walls defining an inboard hole and an outwardly extending lip having walls defining an outboard hole, the outboard hole being opposed to the inboard hole. A support member extends through the inboard hole, and the outboard hole.
In yet another aspect, the sled includes a strap-engaging member for receiving a shear force from a strap engaged thereto and a hull having an extended support region for receiving the strap-engaging member. The extended support region is configured to suppress pivoting of the strap-engaging member in response to the shear force.
In one embodiment, the extended support region can include a wall forming an inboard aperture for receiving a proximal portion of the strap-engaging member and a wall forming an outboard aperture for receiving a distal portion of the strap-engaging member.
Other embodiments include those in which an anti-rotation element is disposed to suppress rotation of the strap-engaging member when the strap-engaging member is engaged by the extended support region. The anti-rotation element can include, for example, restraining fins extending from the hull. The restraining fins are disposed to be in mechanical communication with the strap-engaging member when the strap-engaging member is engaged by the extended support region.
These and other features of the invention will be apparent from the following detailed description and the figures, in which: